i would have to dissagree on some of this i have been researching alot lately into chicken genetics...and all the information i have found on upwards of 10 (all ive researched in cluding the orp.. Had much better egg production at the turn of the century than they do now i read the same statistic (old show stats) of upwards of 300 eggs a year of a deep dark brown color and was a good meat bird what has killed the utility function in all breeds so far as i can tell and this is not just my opinion is show breeding instead of breeding for production traits firstMost of this has no bearing in reality as Saladin said.
FYI an Orpington should never come close to laying that, they are a dual purpose breed and the qualities that make better layers make worse meat animals and vice versa.
Back in the old days egg production was very low, a lot had to do with feeding as nutritional sciences have advanced so has production in all aspects of poultry. Genetics plays a role too, but it comes at the cost of losing breeds identities.
FYI, with proper line breeding you can increase productive qualities, not hinder them. Having to bring in new blood all the time is the sign of a bad breeder.